[Plugin: WP Super Cache] again about mod_deflate

i have just written about it in http://wordpress.org/support/topic/416463?replies=6 ))
but let i write further in dedicated topic.

1. i have it installed and it works.
2. i do not know, whether something is double gzipped.
3. in a meta file i have: a:5:{s:7:”headers”;a:7:{s:4:”Vary”;s:12:”Vary: Cookie”;s:13:”Last-Modified”;s:44:”Last-Modified: Sun, 11 Jul 2010 19:19:48 GMT”;s:7:”Expires”;s:38:”Expires: Wed, 11 Jan 1984 05:00:00 GMT”;s:12:”Content-Type”;s:38:”Content-Type: text/html; charset=UTF-8″;s:10:”X-Pingback”;s:49:”X-Pingback: http://qdinar.wp.localhost/xmlrpc.php”;s:13:”Cache-Control”;s:51:”Cache-Control: no-cache, must-revalidate, max-age=0″;s:6:”Pragma”;s:16:”Pragma: no-cache”;}s:3:”uri”;s:20:”qdinar.wp.localhost/”;s:7:”blog_id”;s:1:”2″;s:4:”post”;i:0;s:3:”key”;s:91:”qdinar.wp.localhostqdinar.wp.localhost80/admin|1279629385|7e6663125f82a0c4918d9d6dd013fcfa,”;}
i do not know, what means absence of “content-encoding” here. i think i can test/check whether it gzips and sets header with temporarily disabling mod_deflate. this meta is used by “wp-cache” caching, but it is said/reported that mod_deflate breaks “wp-cache” and not “super-cache”:

I think this started with the latest WP-Supercache (0.6.5), but the normal (old style) WP-Cache part doesn’t seem to work anymore on my end.

at http://wordpress.org/support/topic/192864?replies=3#post-816467 .
donncha, may be you explain a bit, what does mean absence of “content-encoding” in .meta files? it is also was like asked already by pincode404 :

without a corresponding ‘content-encoding: gzip’ header in ./meta.

at http://wordpress.org/support/topic/192864?replies=3#post-816467 and confirmed by Murmatron 2 and now by me.
3. but donncha has said:

The plugin does set the Content-Encoding header when cache files are gzipped.

at http://wordpress.org/support/topic/262102?replies=2#post-1045533
4. and Murmatron 2 has said:

If the Content-Encoding header is in fact missing, mod_deflate would zip the already zipped data. Some browsers don’t like that very much.
mod_deflate definitely won’t encode (I checked the 2.2.9 source to verify) if a Content-Encoding header is already present in its input (it doesn’t care what the encoding is claimed to be).

at http://wordpress.org/support/topic/192864?replies=3#post-816556
5. donncha has said:

mod_deflate doesn’t store the compressed page so it actually makes your server work harder by running gzip on every request

at http://wordpress.org/support/topic/192864?replies=3#post-817081 .
i understand now, supercache stores ready gzipped files. but when generally in sites mod_deflate is used, it does not use/cache ready gzipped files. i hope that after rewrite rule sends gzipped file, deflate is not applied to output, since mod_rewrite sets content-encoding header. look wp-content/cache/.htaccess :
AddEncoding gzip .gz
and i think, even if mod_deflate gzips on every request, it loads server and client side processor, but file can arrive to user faster, depending on network speed, it depends on network speed of server-side also, and load rate of network and processor, whether to use mod_deflate, i say this accounting it gzips only files like css, js, and dynamic html is gzipped by wordpress (only).